605 research outputs found
Seasonal contribution of living phytoplankton carbon to vertical fluxes in a coastal upwelling system (Ría de Vigo, NW Spain)
The aim of this study is to explore the contribution of living phytoplankton carbon to vertical fluxes in a coastal upwelling system as a key piece to understand the coupling between primary production in the photic layer and the transfer mechanisms of the organic material from the photic zone. Between April 2004 and January 2005, five campaigns were carried out in the Ría de Vigo (NW Iberian Peninsula) covering the most representative oceanographic conditions for this region. Measurements of particulate organic carbon (POC), chlorophyll-a (chl a), phaeopigments (phaeo), and identification of phytoplankton species were performed on the water column samples and on the organic material collected in sediment traps.The POC fluxes measured by the sediment traps presented no seasonal variation along the studied period ranging around a mean annual value of 1085±365mgm-2d-1, in the upper range of the previously reported values for other coastal systems. The fact that higher POC fluxes were registered during autumn and winter, when primary production rates were at their minimum levels points to a dominant contribution of organic carbon from resuspended sediments on the trap collected material. On the contrary, fluxes of living phytoplankton carbon (Cphyto) and chl a clearly presented a seasonal trend with maximum values during summer upwelling (546mgm-2d-1 and 22mgchl am-2d-1, respectively) and minimum values during winter (22mgm-2d-1 and 0.1mgchl am-2d-1, respectively). The contribution of Cphyto to the vertical flux of POC ranged between 2% and 49% in response to the pelagic phytoplankton community structure. Higher values of Cphyto fluxes were registered under upwelling conditions which favour the dominance of large chain-forming diatoms (Asterionellopsis glacialis and Detonula pumila) that were rapidly transferred to the sediments. By contrast, Cphyto fluxes decreased during the summer stratification associated with a pelagic phytoplankton community dominated by single-cell diatoms and flagellates. Minimal Cphyto fluxes were observed during the winter mixing conditions, when the presence of the benthic specie Paralia sulcata in the water column also points toward strong sediment resuspension.Financial support came from CICYT projectREN 2003-04458 and EU projectEVK3-19 CT-2002-00071. D.Z. is funded by a postdoctoral fellowship (Jae-Doc) from the CSIC.Peer reviewe
Influence of mussel culture on the vertical export of phytoplankton carbon in a coastal upwelling embayment (Ría de Vigo, NW Iberia)
14 páginas, 2 tablas, 8 figurasThe goal of this paper is to find out whether suspended mussel culture affects the vertical fluxes of biogenic particles in the Ría de Vigo on a seasonal scale. With this aim, vertical fluxes of particulate organic carbon (POC) and the magnitude and composition of vertical export of phytoplankton carbon (Cphyto) collected in sediment traps were examined by comparing data obtained inside a mussel farming area (RaS) with those found at a reference station (ReS) not affected by mussels. Our results indicate that mussel farming has a strong impact on sedimentation fluxes under the rafts, not only increasing POC flux but also altering the magnitude and composition of Cphyto fluxes. Average POC flux at RaS (2564 ± 1936 mg m−2 day−1) was four times higher than at ReS (731 ± 276 mg m−2 day−1), and much of this increase was due to biodeposit fluxes (Cbiodep) which accounted for large proportion of POC flux (35–60 %). Indeed, because of this high Cbiodep flux, only a small proportion of the POC flux was due to Cphyto flux (3–12 %). At the same time, we observed an increased sedimentation of phytoplankton cells at RaS that could be explained by a combination of mechanisms: less energetic hydrodynamic conditions under mussel rafts, ballast effect by sinking mussel feces, and diatom aggregates. Moreover, mussel farming also altered the quality of the Cphyto flux by removing part of the predatory pressure of zooplankton and thus matching diatom composition in water column and sediment trapsFinancial support came from MICINN RAFTING project (CTM2007-61983/MAR, CTM2007-30624-E/MAR). D. Z. was funded by a postdoctoral fellowship (Plan I2C) from Xunta de GaliciaPeer reviewe
Abnormal mineralization of the Ts65Dn Down syndrome mouse appendicular skeleton begins during embryonic development in a Dyrk1a-independent manner
The relationship between gene dosage imbalance and phenotypes associated with Trisomy 21, including the etiology of abnormal bone phenotypes linked to Down syndrome (DS), is not well understood. The Ts65Dn mouse model for DS exhibits appendicular skeletal defects during adolescence and adulthood but the developmental and genetic origin of these phenotypes remains unclear. It is hypothesized that the postnatal Ts65Dn skeletal phenotype originates during embryonic development and results from an increased Dyrk1a gene copy number, a gene hypothesized to play a critical role in many DS phenotypes. Ts65Dn embryos exhibit a lower percent bone volume in the E17.5 femur when compared to euploid embryos. Concomitant with gene copy number, qPCR analysis revealed a ~1.5 fold increase in Dyrk1a transcript levels in the Ts65Dn E17.5 embryonic femur as compared to euploid. Returning Dyrk1a copy number to euploid levels in Ts65Dn, Dyrk1a+/− embryos did not correct the trisomic skeletal phenotype but did return Dyrk1a gene transcript levels to normal. The size and protein expression patterns of the cartilage template during embryonic bone development appear to be unaffected at E14.5 and E17.5 in trisomic embryos. Taken together, these data suggest that the dosage imbalance of genes other than Dyrk1a is involved in the development of the prenatal bone phenotype in Ts65Dn embryos
The Dietary Antioxidant Piceatannol Inhibits Adipogenesis of Human Adipose Mesenchymal Stem Cells and Limits Glucose Transport and Lipogenic Activities in Adipocytes
Phenolic compounds are among the most investigated herbal remedies, as is especially the case for resveratrol. Many reports have shown its anti-aging properties and the ability to reduce obesity and diabetes induced by high-fat diet in mice. However, such beneficial effects hardly translate from animal models to humans. The scientific community has therefore tested whether other plant phenolic compounds may surpass the effects of resveratrol. In this regard, it has been reported that piceatannol reproduces in rodents the anti-obesity actions of its parent polyphenol. However, the capacity of piceatannol to inhibit adipocyte differentiation in humans has not been characterized so far. Here, we investigated whether piceatannol was antiadipogenic and antilipogenic in human preadipocytes. Human mesenchymal stem cells (hMSC), isolated from adipose tissues of lean and obese individuals, were differentiated into mature adipocytes with or without piceatannol, and their functions were explored. Fifty mu M of piceatannol deeply limited synthesis/accumulation of lipids in both murine and hMSC-derived adipocytes. Interestingly, this phenomenon occurred irrespective of being added at the earlier or later stages of adipocyte differentiation. Moreover, piceatannol lowered glucose transport into adipocytes and decreased the expression of key elements of the lipogenic pathway (PPAR gamma, FAS, and GLUT4). Thus, the confirmation of the antiadipogenic properties of piceatanol in vitro warrants the realization of clinical studies for the application of this compound in the treatment of the metabolic complications associated with obesity.This project has been partially supported by grants from Interreg POCTEFA, European Union, via Refbio-the Pyrenees Biomedical Network, also by the project PI17/02268 (Instituto de Salud Carlos III. Madrid, Spain) and by Fondo Europeo de Desarrollo Regional (FEDER) funds: "Una manera de hacer Europa"
Impact of atmospheric deposition on the metabolism of coastal microbial communities
11 páginas, 3 tablas, 5 figurasThe impact of rain water collected at marine, urban and rural sites on coastal phytoplankton biomass, primary production and community composition as well as the effect on microbial plankton metabolism was studied in 3 microcosm experiments conducted under contrasting spring, autumn and winter conditions. The measured responses were highly variable. Rainwater additions increased chlorophyll a (Chl a) concentration (5–68% difference between rainwater treatments relative to the control) in all experiments and reduced or stimulated primary production (PP) depending on the treatment and the experiment (from −10 to +169% relative to the control). Autotrophic stimulation was highest in spring, probably related to the low initial natural nutrient concentrations. Under winter nutrient replete conditions, rainwater inputs changed the phytoplankton community although this change did not promote increases in primary production. Enhancement of net autotrophy (increase of net oxygen production up to 227%) after rainwater inputs were only found during the period of low nutrient availability. Inputs of dissolved organic nitrogen (DON) explained a large fraction of the variability in the response of PP, Chl a, community respiration (CR) and net community production (NCP). Our results suggest that differences in the initial environmental conditions (i.e. nutrient availability), rainwater composition and the ability of the present autotrophic communities to utilize the new nutrients result in substantial changes in the microbial responses and associated biologically-mediated carbon fluxes. As atmospheric nutrient inputs into coastal oceans are increasing rapidly, our results help to understand the effects of different inputs on the metabolism of distinct microbial communitiesThis research was supported by the Galician Government (Xunta de Galicia) through the grants 07MMA002402PR (IMAN) and PGIDIT06PXIB312222PR (AddEx). S.M-G. and E.E.G-M. were funded by F.P.U. fellowships and E.T. by a Ramón y Cajal contract of the Spanish Ministry of Science and InnovationPeer reviewe
Physical Activity Participation in Rural Areas: A Case Study
Sport participation and physical activity promotion have been intensively studied, especially regarding large cities. However, in many cases, rural municipalities have comparatively
reduced services, including health care, due to the low profitability that these have for companies
and entities. In this sense, the purpose of this article was to describe a case study of the promotion
of physical activity in rural areas based on the results of a European project. Carried out in a rural
municipality of around 8500 inhabitants with a population density of less than 25 inhabitants/km2
,
the project’s purpose was the promotion of autonomous physical activity among its inhabitants. For
this, a diagnostic analysis of the sports areas of the environment and a survey of physical activity
habits among the population were carried out. A series of routes were designed, marked, and signposted, and canopies with explanatory posters about the possibilities of healthy physical activity and
recommendations were added. Free-use facilities were installed, and opening events were carried
out in such a way as to stimulate sports practice among the population. This article presents the
results obtained from the analysis, as well as the possibilities of replication in other municipalities
with similar needs
Deep learning: creating bridges between DMPs in autoencoders and recurrent neural networks
The complexity in modeling human movement increases as the dimensionality of these movement grows.
Since searching more precision and flexibility involves more variables in the model. Dynamic Movement
Primitives (DMP) have shown the ability to generate joint movements with high complexity. However, the
problem remains in the interaction between several joints since DMP alone is not able to deal with it. To solve
this problem a new model called autoencoded dynamic movement primitive (AE- DMP) is introduced in the
work "Efficient movement representation by embedding DynamicMovement Primitives in Deep Autoencoders"[2].
The proposed approach uses autoencoder in order to find a representation of the movement in a latent space.
Consequently, the DMPmodel is able to reconstruct the complete movement. In thisMaster Thesis we will study
the implementation of this model and study its performance. All the features stated in the original paper are
checked, as multiple movements, sparsity and reconstruction of missing or corrupted data
Internet-based medical education: a realist review of what works, for whom and in what circumstances
http://creativecommons.org/licenses/by/2.0
Microbial Community Composition during a Bloom of Purple Bacteria in Intertidal Sediments in Vigo (Northwest Spain)
In summer 2019, a large, bright pink microbial mat was visible on top of macroalgal deposits in muddy sediments of an urban beach (Playa do Adro, Vigo). In order to characterize the dominant organisms in these colored mats, results from microscopic observations, photosynthetic pigments, and molecular analysis were gathered. Light microscopy examination revealed pinkish microbial aggregates with minor contributions of larger protists and cyanobacteria. High-performance liquid chromatography (HPLC) pigment analysis documented the dominance of bacteriochlorophyll a and carotenoids whose spectra were compatible with those described in photosynthetic purple bacteria. 16S rRNA gene amplicon sequencing confirmed that the vast majority of reads belonged to Proteobacteria (73.5%), and among them, nearly 88% of those reads belonged to purple sulfur bacteria (Gammaproteobacteria). A single family, Chromatiaceae, constituted the bulk of this assemblage, including the genera Thiohalocapsa (32%), Marichromatium (12.5%), Phaeochromatium (5%), and Halocromatium (2%) as main contributors. Nonetheless, a considerable number of sequences could not be assigned to a particular genus, stressing the large biological diversity in these microbial mats and the potential presence of novel taxa of purple sulfur bacteria.En prens
Expandibilidad del tejido adiposo: Identificación de nuevas dianas terapéuticas
La obesidad es una enfermedad crónica de origen multifactorial que se define fisiológicamente como una acumulación de grasa que causa problemas de salud. Actualmente está aceptado que el tejido adiposo no es un mero almacén de energía y es considerado un órgano endocrino extraordinariamente heterogéneo en cuanto a su composición y a su distribución corporal. Aproximadamente el 85% de la masa total de tejido adiposo es subcutánea, mientras que el 15% restante constituye grasa visceral..
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